James Maxwell's EM Wave

"I have the capacity of being more wicked than any example that man could set me"
-James Clerk Maxwell [1853]

He was a brilliant electromagnetic theorist a apparently very naughty man. Maxwell calculated that the speed of propagation of an electromagnetic field is approximately that of the speed of light. He proposed that the phenomenon of light is therefore an electromagnetic in origin. Because charges can oscillate with any frequency, Maxwell also concluded that visible light forms only a small part of the entire spectrum of possible electromagnetic radiation. (see post on frequency allocations 6/15)

The theoretical basis for the propagation of electromagnetic waves was first described in 1873 by James Maxwell in his paper to the Royal society in London A dynamical theory of the electromagnetic field, which followed his work between 1861 and 1865.

Maxwell had unified the work of previous electromagnetic and optical experiments reducing their results into a set of equations. These equations with his own work have become the basis for transmitting. he produced the actual laws of electromagnetism most importantly electromagnetic radiation. The equations are fundamental to the broadcast of radio and television.

bio here: http://www.phy.hr/~dpaar/fizicari/xmaxwell.html

He was also a notorious late-night carouser. When informed at Cambridge that cumpulsory church services began at 6:00 am he relpied "Aye, I suppose I could stay up that late." Spoken like a true radio man.

KPH: The Wireless Giant of the Pacific

Every year on August 12th KPH returns to the air for one night...

According to the Maritime Radio Historical Society, the station would have been 100 this year. It began in 1905 as Morse station "PH." (Remember back then call letters were voluntary. You could make up anything you wanted.) The call letters referred to the Palace Hotel in San Francisco, where the station was located. Later, regulators later added the K to the call sign. KPH was once known as the "Wireless Giant of the Pacific."

For almost a century, marine wireless operators heard steady dots and dashes of the KPH signal in their earphones. At KPH some of the best Morse operators in the country listened for calls from ships. Most messages were routine. But occasionally an S-O-S would come in and KPH operators would jump to respond. The station went silent in 1997; two years before the formal end of commercial Morse Code use in the United States.

The annual event is July 12 this year; it is held at Point Reyes Station in California. Organizers have invited the public to watch professional Morse operators, including several original KPH operators, work the station. The station moved its transmitters and receivers to West Marin in the 1920s. The Maritime Radio Historical Society keeps it alive, with cooperation of the Point Reyes National Seashore. The Point Reyes National Seashore currently owns the land and buildings and all the artifacts of KPH.

Pedal Radio

In 1907 Alfred Traeger a farm boy in Australia amazed his family by building a phone between their house and a barn 50 yards away. He had no professional hardware. His magnets were made from pitch fork prongs, the diaphragms from tobacco tin lids, and the charcoal for carbon granules came from the kitchen stove. his parents decided to send him to electrical engineering school. Before he was 20, Traeger had built a transmitter and was sending Morse code.

Radio in Australia (like the US) took off in the 1920s. The problem was reaching the masses. Australia is a big place. Its land area is four-fifths that of America U. S., and it is rightly its own continent. Only eighty-five percent of the country's population lives in urban areas, mostly on the eastern and southern seaboards. So when radio got popular, it was hailed as the solution for rural loneliness in the outback. The rural residents of "the interior" couldn't afford the sophisticated 5-tube radios. And Even when they did, they usually didn't have AC power (let alone plumbing) to use it!

Alf invented The pedal wireless radio. By 1927 he was demonstrating two way pedal wireless. The user simply pedals to power a generator while sending Morse code. This was a hit with lonely homesteads, remote mission stations, and even aboriginal communities "The Bush Network" as they called it, quickly grew to cover much of the remote center and northern areas.

Then in 1931 Alfred invented an automatic Morse code keyboard! It was like a normal typewriter. Resembling a typewriter, each key was connected to a pivoted steel bar with notched spacings corresponding to the Morse alphabet. he was determined to make radio available to everyone. In 1995 Fred McKay wrote a book on the man... i haven't read it yet, But I fully intend to.

KISL Island radio

Catalins island is 63 miles off the coast of Los Angeles, California. There is one lone radio station on that island. KISL-FM operates at 88.7 Mhz with 200 watts ERP. It covers the city of Avalon quite well, and can be heard 26 miles away along the coastline and also in the mountains of Southern California as well.

check out their webcam:
http://www.cipaf.org/javawebcamwindow.htm

KISL's tower is on a hill above the town of Avalon and the Avalon Harbor. It was a hot July 5th when I took the one-hour trip by jet boat to Catalina Island with installation gear and Ken Horton as my able assistant. David Markowitz and Ron Thompson formerly of the legendary KLON built this little gem pretty much by themselves I am told.

check out their webcam
http://www.cipaf.org/javawebcamwindow.htm

antenna pics here: http://www.well.com/user/dmsml/kisl/

The Radio Merit Badge

Honestly I am not sure I could pass this test. I have sampled some of the questions for the Boy Scouts of America Radio Merit badge exam below. click my header for the full test in PDF or
go here: http://www.meritbadge.com/mb/093.htm

1. Explain what radio is. Include in your explanation: the differences between broadcast radio and hobby radio, and the differences between broadcasting and two-way communicating. Also discuss broadcast radio and amateur radio call signs and using phonetics.

2. Sketch a diagram showing how radio waves travel locally and around the world. How do the broadcast radio stations, WWV and WWVH, help determine what you will hear when you listen to a radio?

3. Do the following:
a. Draw a chart of the electromagnetic spectrum covering 100 kilohertz (kHz) to 1000 megahertz (MHz).
b. Label the MF, HF, VHF, UHF, and microwave portions of the spectrum on your diagram. Locate on your chart at least eight radio services such as AM and FM commercial broadcast, CB, television, amateur radio (at least four ham radio bands), and police.
c. Discuss why some radio stations are called DX and others are called local.
d. Explain who the FCC and the ITU are.

4. Explain how radio waves carry information. Include in your explanation: transceiver, transmitter, amplifier, and antenna.

5. Explain to your counselor the safety precautions for working with radio gear, particularly direct current and RF grounding.

6. Do the following:
a. Explain the differences between a block diagram and a schematic diagram.
b. Draw a block diagram that includes a transceiver, amplifier, microphone, antenna, and feedline.
c. Explain the differences between an open circuit, a closed circuit, and a short circuit.
d. Draw eight schematic symbols. Explain what three of the represented parts do. Find three electrical components to match to three of these symbols.

holy frijoles.
I want to meet just one boy scout with this damn badge.